Capacity stabilizing device



Sept. 8, 1931. P. E. EDELMAN CAPACITY STABILIZING DEVICE 2 Sheets-'Sheet 1 Filed Feb. 17, 1927 INVENTOR.

A TTORNEYS Sept. 8, 1931. P. E. EDELMAN 1,822,728

CAPACITY STABILIZING DEVICE Filed Feb. 17, 1927 2 Sheets-Sheet 2 WA VELE NG TH IN VEN TOR.

ATTORNEYS Patented Sept. 8, 1931 UNITED STATES PATENT OFFICE PHILIP E. EDELMAN, OF CHICAGO, LIJI'IGIS, ASSIGOR TO THE CROSLEY RADIO COR- PORATION, OF CINCINNATI, GHIG, A CORPORATIGN OF OHIO CAPACITY STABILIZING DEVICE Application filed February 17, 1927. Serial No. 169,075.

Vagainst undesired oscillation, by means of a device which has good eiiiciency throughout v the range of adjustment of the amplifier, be-

cause of the stabilization being so arranged as to be proportional to the wave length adjustment of the apparatus.

It is my object to adapt my invention for use with separate or unit control systems for activating a series of tuning condensers, and preferably to employ as stabilizing capacifties, small electrostatic elements which are placed to have electro-static coupling to the stator and rotor partsof the condensers, the arrangement being such that the electrostatic coupling to the stator elements of the condensers is less at longei wave lengths, thereby giving variable stabilizing effect.

It is my object to employ more than one electro-static stabilizing element with each condenser, which permits me to introduce adjustable features for some and not al1 of the stabilizers, and particularly permits me to distribute the lines of stabilization in such a way as to effect all of the condensers for the several amplifying stages, without connecting all of the stabilizing capacities 'together, and thus providing a possible 1mproper coupling. D

My invention is applicable in principle to inductances as Well as capacities, and in its generic aspect covers the use of stabilizing capacities or inductances which are so arranged mechanically with tuning the condensers or inductances, that the change of relative positions of the parts of the capacities or inductances in timing will at the same time change the relationship of the stabilizing elements to tuned elements, and thus change the stabilization. I

I accomplish my objects by that certain construction and arrangement of parts to be hereinafter more specifically pointed out and claimed.

In the drawings Figure 1 is a diagram showing the arrangement of tuning elements and stabilizing elements in a multi-stage receiver having four condensers in line, adjusted from a conimon mechanical source, to impart tuning.

Figure 2 is a detail front elevation of a condenser arrangement showing the relation of stabilizers to rotor and stator plates.

Figure 3 is a side elevation showing the relation of said parts from the side.

Figure et is an efficiency diagram.

Figure is a wiring diagram showing the invention as applied to tuned radio frequency circuits.

The condensers are shown at stages 1, 2, 3 and et, and as housed in a compartment type of casing having a separate metal compartment 5 for each condenser. They are arranged in a multi-stage timed radio frequency receiver having tubes 1a, 2a, 3a and 4a, with coupling transformers 1b, 2b, 3?).

The rotor plates of the condensers are shown at 5a and the stator plates at 6. The rotor plates are mounted, in this instance, on a common shaft 7, which is operated from a knob 8 located so as to be available to the operator.

In the particular instance shown, the stator plates are insulated from the'frame of the machine, and the rotor plates are grounded to the frame by means of conductors 9 secured to the common shaft and also secured to the frame.

In the instance shown, there are two stabilizing capacities for each condenser. Considering the condensers as being mounted in the compartments 5,.with the stator plates held on pieces of insulation 10, I mount the stabilizing capacities on blocks of insulation 11 held on the compartment walls, so that the capacities 12, 13, for the first of the condensers for example, will be set so as to face the outer set of rotor plates of that condenser with whatever spacing that may be required to give the desired coupling.

The capacities 14e and 15, for the second condenser, 16 and 17 for the third, and 18 and 19 for the fourth Will be mounted in a like ranged to suit conditions.

manner, if desired, or in any iXed or adjustable manner.

By reference to Figure 3, it will be noted that when the condensers are open the capacities of each stabilizing element will be exposed to the stator plates 6, with the rotor plates swung out of the way, but that when the rotor plates are in the most closely coupled position, that they blank oli the stator plates from having any marked effect upon the stabilizing capacities.

The intermediate positions will be variables between the two extremes. Also the two stabilizing capacity plates for each tuning condenser will be shaped and positioned so as to give the same orv different variances upon adjustment of the condenser, and as illustrated in Figure 3, the shape of the two platesmay be different, thus resulting in having a variable between the two as applied to one condenser, and'- also varying the progressive change inl relation tothe condenser it self, as to eachV of the two.

In the arrangement shown, the stabilizer plates 13 and 14 are connected to each other as at 12a, the plates 17 and 18 connected to each other` as at 16a, the plates 12 and'19 connected by the Wire 13a, which has a switch 135 therein, andthe plates 15 and 16 connected together as at 15a.

Thel plates are insulated from ground or otherV potential carryingl parts, as are the connections between them, and the connections, and other variables noted can be ar- In the illustration in which the relationship of Figure 3 and the connections of Figure 1 have been adopted, the eiiect is-to provide an automatic potential equalizer system which is adjusted in value to correspond to diiierent settings of the controlv knob, so that the rotors cut out most or all of thc potential equalizer effect when adjusted for higher wave lengths, thereby keeping amplification uniformly good throughout the range of the receiver;

In the usuali fixed potential equalizers, the usual fixed stabilizers provide too much interconnection at high: Wave lengths and cuts out amplification at the lower wave lengths.

It can` be seen that by increasing the size of the insulation block, the setting of any of the stabilizing plates can be arranged to obtain an adjusted capacity coupling.

In the diagramof Figure 4 I have indicated the line 102, which indicates the usual falling ofi of amplification as the wave lengths become higher in a tuned radio frequency receiver where no stabilizing is used. Where fixed neutralizing or balancing means V are made use of, so arranged as to give efiicient ampliications at such higher Wave lengths,.thenthe receiver oscillates or squeals at settings around' points shown by numera1'104.

This is avoided' by the present invention which automatically adjusts the amount of balancing to fit the wave length adjustment, as indicated by the curve 101. In its most general aspects, my invention difi'ers from neutralizing systems of which II have knowledge, in that the coupling of the balancing elements is electro-static rather than by direct contact as is customary.

Various changes or modifications may be made Within the scope of the appended claims. The particular way of connecting the stabilizer plates together results in avoiding any regular relationship which would give rise to dangers of improper action ofthe receiver, since the several condensers are not connected by the stabilizers as a group, and still each condenser is stabilized with relation to-each of the others.

Having thus describedl my invention, what I claim as new and desire to secure by Letters Patent, is

1. In a radio system, a series of ampliers with tuning condensers for each stage ofsa/id series, extra condenser plates inserted in the fields of said condensers, and conductors joining said extra condenser plates from one of said stages to another to feed energy between one stage and another Vin said series in amount proportioned to the tuning adjustment of said condensers.

2. In a cascade radio amplifier including tuning condensers in each stage thereof, a capacity areal inserted in the tieldsof said condensers and arranged to have adjustable capacity with respect thereto as said condensers are adjusted, and means to connect said capacity areas inv groups between said condensers to feed energy therebetween.

3. In a radio receiver, a series of tuned ampliiier stages each having a tuning condenser including a balancing condenser late inserted in the field thereof, means to a just said tuning condensers and simultaneously change the capacity of said condenser plate with' respect thereto, yand means to feed energy from one of said tuning condensers to another in the series via said inserted condenser plate.

l. In ay tuned radio frequency receiver having tuning condensers associated with vacuum tubes forming aseries of coupled amplifying stages, means for neutralizing the interaction of said stages with relationto each other as described, comprising elements connected to eachother, and having a capacity coupling with the condensers.

5. In a tuned radio frequency receiver ha-ving tuning condensers associated with vacuum tubes forming a series of coupled amplifying stages, means for neutralizing the interaction of said stages With relation to each other as described, comprising elements connected to each other, and having aV capacity coupling with the conednsers, said coupling being variable with the movement vlo of the condenser parts in tuning the same.

6. In a tuned radio frequency receiver having tuning condensers associated with vacuum tubes forming a seriesof coupled amplifying stages, means for neutralizing the interaction of said stages with relation to each other as described, comprising elements connected to each other, and having a capacity coupling with the condensers, and one of them at least located Within a portion of the field of its condenser which is varied by the movement of the rotor thereof.

PHILIP E. EDELMAN. 

